check engine light wiring how to

[htibaja]

Hey guys i put a 1uz into a toyota pickup offroad race truck and have it all up and running but need to diagnose an issue but cant seem to figure how to wire a cel.

Am this far. I connected te1 and e1 in the engine diagnostic plug but can not find which wire coming out of the ecu to trip the engine light on and off. Using a small green led next to my switches as the engine light so there is no gauge cluster or dash all wired in race gauges.

I have the 40/40/40 out of a 93 sc400 ecu

 

[gloverman]

Pin 6 of plug A is the check light. It should also be in the engine diagnostic plug on the engine. Cheers

 

[htibaja]

So i connected te1 and e1 then connected a test light to 12 v positive and checked every wire that could have been pin 6 since i didnt know whick plug was A and couldnt get a signal out of any wire. If i am correct it should be a pulsing signal

 

[gloverman]

IS there a W terminal in your diagnostic connector on the engine?

 

[htibaja]

attached is the diagnostic port on the motor exactly. dont have an under dash port

 

[gloverman]

Is there a pin in the W?? This is a check light output , if it has a pin. Using you test light connect to battery power(or B+ terminal) and with the key on engine off the light should illuminate. If not you have other issues. If the light does work start the engine it should go out. To extract codes as you know, Bridge Te1 and E1 and using a test light with one end to power and the other to the W pin it should flash. I always wire the under dash connector to connect a scanner and get live data but you still need a check light on the early ones as the scanner counts the flashes of the light. No light no flashes no codes with a scanner. Cheers

 

[htibaja]

Sweet thanks man ill give it a try

 

[htibaja]

Well checked today and there is no pin in w and no wire running to it so the easy way isnt gonna work. Am i just gonna have to go through and check every wire coming out of the ecu?

 

[Bushwhacker]

ECU pin #6 in this diagram is the check light (W) blue/yellow, for your engine.
http://www.lextreme.com/PDF/scecu2.pdf

 

[htibaja]

So checked that wire again with multimeter, positive to 12v source and negative to the #6 blue\yellow and there is no signal. No signal at all when i turn on the ignition or when i have te1 and e1 bridged. Dont get it the truck runs but the ecu wont throw a signal for engine light. I am stuck because i need to diagnose why motor is running shitty when maf is plugged in. Anybodys ideas would be greatly appreciated

 

[stevieg]

It's usually a green/white wirefor the check engine light

 

[gloverman]

I can see two possible reasons the check light isn't working. Stuffed ECU or it's wired wrong. Have seen both with the wiring option being more popular. Cheers